See the Great Equatorial Telescope

Coronavirus reopening

Visitor notice: All of our sites have reopened and we can't wait to welcome you back. All visitors will need to book a ticket in advance. Find out how we're keeping you safe

Essential information

Opening times: 
10am–5.30pm daily
Royal Observatory, Great Equatorial Telescope gallery

Stand beneath the magnificent onion dome and marvel at one of the biggest telescopes in the world. Join one of our special Evenings with the Stars and look through the telescope yourself.

The 28-inch Greenwich refracting telescope is the largest of its kind in the UK and the seventh largest in the world. It was built to research double star systems and remained in use until the late 1960s. With the recent addition of a computer-aided guidance system and CCD camera, it continues to work as an excellent visual aid to observing the night sky.

  • Marvel at one of the biggest telescopes in the world. 
  • The Onion dome was originally made from papier mâché, but now is fibreglass. 
  • Get up close and personal with the stars by visiting for free, or booking one of our Evening with the Stars events. 

Telescope facts 

It took eight years to make and was a great success in the Royal Observatory’s programme of double star observations. It rests on a mount built 30 years earlier for a smaller telescope. The telescope tube is over 28 feet (8.5 metres) long and is round at each end but rectangular in the middle. This is because its mount was built for a much smaller telescope, so the middle section of the tube had to be tapered in order to fit. Attached to the outside of the tube are smaller telescopes, used as guides to target an object or to magnify the telescope’s scales. The mount allows the telescope to be rotated on the same axis as the Earth, so it can follow a star from east to west across the sky.

Find out more about the Great Equatorial Telescope